Seigo MiyamotoOn the behalf of every emulsion

users and developers

Nuclear emulsion: the review of the recent observationsand the development of technologies

1Muon and Neutrino Radiography 2013, 26th June, Tokyo.

Detector : Nuclear emulsion film

Muon and Neutrino Radiography 2013, 26th June, Tokyo. 2

Detector : Nuclear emulsion film

• No power supply

• Compact

• Good stability for hard environment,except > 30 ℃

• The real-time monitoring is not available

Need development and scanning by automated readout system

150 micron

microscopic image

Recorded as silver grains along the line particle passed through

Muon and Neutrino Radiography 2013, 26th June, Tokyo. 3

Break through in 2006

Muon and Neutrino Radiography 2013, 26th June, Tokyo. 4

Tanaka and Nakano et al., 2007

Recent observations and going-on projectsby emulsion detectors

5Muon and Neutrino Radiography 2013, 26th June, Tokyo.

6

Unzen lava dome imaging by Miyamoto et al

Detector is here

Muon and Neutrino Radiography 2013, 26th June, Tokyo.

Tan = -0.60 rad - 30 deg

Tan = +0.60 rad+30 deg

7

Observed muon/Expected ratioTa

n( e

leva

tion

- 10.

5 de

g )

Tan( azimuth - 127.5 deg )Tan( azimuth - 127.5 deg )

AC

B

Tan( azimuth - 127.5 deg )

• The detector cannot discriminate GeV/c particle• A : Observed/Expected > 100 BG dominant• B : Observed/Expected = several BG dominant• C : Observed/Expected < 1.0 It seems no BG ?

100

200

300

500 400

600

Zenith = 90.0 deg

Assuming the density of mountain is 2.5g/cc

8Muon and Neutrino Radiography 2013, 26th June, Tokyo.

Q. What is the BG source ?A. Low momentum particles

• The experimental study on background source of muon radiography using the detector which can discriminate GeV/c order momentum of the particles ( Emulsion Cloud Chamber ) was done around the Mt. Usu and showa-shinzan by Nishiyama et al.

• This study confirms that the source of background noise is low-momenta(<1GeV) charged particles.

StromboliItaly

by Tioukov et al.

The imaging of conduit is critical for the eruption dynamics modelThe preliminary image of Stromboli will be shown.

9Muon and Neutrino Radiography 2013, 26th June, Tokyo.

StromboliItaly

by Tioukov et al.

10Muon and Neutrino Radiography 2013, 26th June, Tokyo.

• Expected diameter of the conduit is 10m or less 10m/500m = 20mrad Very high angular resolution is needed and emulsion detector is suitable for conduit imaging

• Difficult to get the power supply

Mt. Teide @ Tenerife, Canary Island

11

Imaging the shallow part of summit cone by Hernandez, Padron et al

12

Beam of cable car buildingW 2.5m x D 0.3m x H 0.7m

Emulsion Cloud Chambers 0.5 m2 includes two 1mm-thick lead plates.

Muon and Neutrino Radiography 2013, 26th June, Tokyo.

PRO

JECT

SThe imaging of La Palma Fault in 1949

13

Hernandez, Padron et al.

The emulsion detector will be installed in this October.

Muon and Neutrino Radiography 2013, 26th June, Tokyo.

PRO

JECT

SThe imaging of La Palma Fault in 1949

• No infrastructure around this site No power supply

• Expected width of the fault is 1m to 10m. Need high resolution

14

Hernandez, Padron et al.

Muon and Neutrino Radiography 2013, 26th June, Tokyo.

The technical development

15Muon and Neutrino Radiography 2013, 26th June, Tokyo.

Large scale production of new emulsion films

• We have been used the emulsion films which was made more than ten years ago.They accumulate all tracks of charged particles passed through Too many background Need to increase threshold to recognize the track in emulsion Muon detection efficiency decrease.

• Morishima et al are going to product the new emulsion film, which consists of very sensitive emulsion gel with the order of ~ 1 m2/day.

16Muon and Neutrino Radiography 2013, 26th June, Tokyo.

QSS “Quick Scanning System”next generation’s scanning system

• QSS are under fine-tuning which consists of low magnification objective lens large field of view.

• 4M pix high-speed camera• Continuous stage moving with constant velocity.• Track recognition by Multiple GPUs.• 150 cm2/hour = 2.7m2/2plates/month/system• By Bozza et al.

17Muon and Neutrino Radiography 2013, 26th June, Tokyo.

The MONSTER readout system : “HTS”

• Sixteen CMOS sensors mounted in the grid discontinuously

• 30cm-diameter objective lens• Very quick movement of XY stage with counter

mass movement.• Track recognition of Multiple GPUs.• 6000 cm2/hour =

108m2/2plates/month/system• By Yoshimoto, Nakano, et al.

18Muon and Neutrino Radiography 2013, 26th June, Tokyo.

Summary

19

• Emulsion detectors have been used/will be used for muon radiography due to its advantage features

• Recent technical development implies that the muon radiography with ~ 10m2 effective area with BG-free (Emulsion Cloud Chamber) is promising.